A broadband circularly polarized antenna

Abstract

A right-handed circularly polarized antenna is proposed with a broadened bandwidth in terms of axial ratio, impedance matching and gain. The antenna consists of a suspended slotted patch and an L-shaped feeding probe. An antenna prototype with an overall size of 250 mm × 250 mm × 50 mm exhibits a measured mimimum gain of 6.4 dBic, axial ratio less than 3 dB, and reflection coefficient less than -10 dB over the frequency band of 800-960 MHz, which makes the antenna suitable for ultra high frequency (UHF) RFID applications.